Magnitude-5.9 quake hits near Fukushima nuclear site (Japan Today, Nov 24)
TOKYO — A strong earthquake struck Thursday morning near the Fukushima Daiichi nuclear power plant hit by a powerful tsunami earlier this year. There were no immediate reports of damage or injuries.
The U.S. Geological Survey said the magnitude-5.9 quake struck shortly before 4:30 a.m. local time. It hit 101 kilometers east of the nuclear power plant. The quake struck at a depth of 37 kilometers.
The Pacific Tsunami Warning Center did not immediately issue a tsunami alert.
Study: Radioactive water reaches international date line (Asahi, Nov 22)
Radioactive water from the damaged Fukushima No. 1 nuclear power plant has reached the international date line, about 4,000 kilometers east of Japan in the Pacific Ocean, according to estimates.
The concentration of radioactive cesium-137 will be 0.1-0.01 becquerel per liter by the end of November, 10 to 100 times higher than before the accident started, according to estimates by the Japan Agency for Marine-Earth Science and Technology.
The concentration will be at one-2,000th to one-20,000th of the government safety standard for potable water, but monitoring will be necessary for any impact on fish and shellfish.
A team of researchers led by Yukio Masumoto estimated the flow based on radiation levels measured in waters around the Fukushima No. 1 plant, taking convection and other factors into account.
Radioactive water that leaked from the plant first moved along the coast and then gradually moved offshore.
The researchers estimated that it reached the international date line in four to five months after spreading amid complex flows between the Oyashio and Kuroshio currents.
Researchers say pond plant may help clean Fukushima (Asahi, Nov 23)
A plant that grows abundantly in irrigation waterways and ponds may be the seed for solving the problem of radioactive fallout in rice paddies contaminated by the Fukushima No. 1 nuclear power plant, according to researchers.
Dwarf hairgrass, or Eleocharis acicularis, is a fast growing plant with long grass-like leaves and is known to absorb heavy metals such as cadmium and zinc.
A team led by Masayuki Sakakibara, professor of biology at Ehime University’s graduate school, found that it also absorbs large quantities of radioactive cesium in the soil.
With help from officials at a prefectural agricultural center in Koriyama, Fukushima Prefecture, Sakakibara’s team planted five kilograms of the plant in containers filled with soil collected from the bottom of the center’s paddies.
The soil contained about 3,800 bequerels of cesium per kilogram. The study found that the plants absorbed a maximum 1,071 becquerels of cesium per kilogram.
Because the absorption process is rapid, the researchers hope that the plant could provide real help in decontamination work following the disaster.
It is not yet clear how the contaminated plants will be dealt with.
The research was conducted as part of reconstruction efforts backed by the Geological Society of Japan.
Fukushima school radiation monitoring equipment failure causes delay (Japan Today, Nov 20)
TOKYO — The Ministry of Education, Culture, Sports, Science and Technology says that a government project to operate real-time radiation monitoring devices at schools and other public
facilities in Fukushima Prefecture will be delayed.
According to NTV, the project, financed under the first supplementary budget for fiscal 2011, calls for the installation of 600 radiation monitoring devices at elementary schools, parks and community centers near Tokyo Electric Power Co’s crippled Fukushima No. 1 nuclear power plant.
The ministry also revealed it had terminated its contract with Tokyo-based supplier Alpha Tsushin after the firm failed to meet a deadline for correcting a problem in the system, NTV reported. The launch of operations, originally scheduled for mid-October, will be delayed to
around mid-February, the ministry said.
SENDAI–There were fears there wouldn’t be much in the way of a strawberry harvest this year, at least in the tsunami-stricken Tohoku region.
But to the delight of consumers, the first shipment of strawberries this season was delivered from a market in Sendai on Nov. 19.
The fruit was harvested in Watari, Miyagi Prefecture, an area with the largest yield of strawberries in the Tohoku region, but also one that was devastated by the Great East Japan Earthquake.
As a result, the first shipment from market came about a month later than usual.
Because so many farms were affected, there has been a huge decrease in the volume of strawberries harvested this year.
Still, market insiders and agricultural cooperative officials celebrated the first shipment of the season as one step toward recovery in the region.
Because so many farms were affected, there has been a huge decrease in the volume of strawberries harvested this year.
Still, market insiders and agricultural cooperative officials celebrated the first shipment of the season as one step toward recovery in the region.
Watari was known for its many strawberry farms along the coast, which was inundated by tsunami spawned by the March 11 Great East Japan Earthquake.
Farmers resumed planting by moving their farms farther inland and planting seedlings from farmers in Tochigi Prefecture.
However, officials of the Miyagi prefectural association of agricultural cooperatives said the total acreage for strawberry farms in the prefecture had decreased this year to about 50 hectares from the approximately 130 hectares of a year ago.
That is expected to lead to a decrease in production volume to less than half of last year’s level.
At a ceremony for the first shipment, Kunio Iwasa, the chairman of the JA Miyagi Watari cooperative, said, “We are glad we were able to make the first shipment in time for Christmas. Even with the major disaster, the feelings toward and technology for growing strawberries were not swept away.”
ONAGAWACHO, Miyagi–About 350 local primary school students on Tuesday toured the USNS Safeguard, a U.S. rescue and salvage ship that had made a port call in the disaster-hit town the previous day.
The Safeguard, with a length of 78 meters and a displacement of 3,282 tons, took part in Operation Tomodachi to assist in the disposal of debris in the waters off Miyako, Iwate Prefecture, and off Kesennuma, Miyagi Prefecture, in the aftermath of the March 11 disaster. It worked on the operation until May.
The ship called at Onagawa Port on Monday to deepen friendship with people in disaster-hit areas.
The children toured the vessel Tuesday, under the guidance of crew members and received gift bags containing stuffed toys, letters, candy and other items.
“I was surprised by the size of the ship and by the sheer amount of equipment such as radar monitors,” said a 9-year-old boy, who is in the fourth grade at a local primary school. “The Americans were kind and looked very strong.”
Smiles return to Tohoku as the circus comes to town (Japan Times, Nov 20) | Disaster zone kids to take to pitch at Wembley (Japan Times, Nov 23)
Radioactive cesium blankets 8% of Japan’s land area (Asahi, Nov 21)
“Some 8 percent of Japan’s land area, or more than 30,000 square kilometers, has been contaminated with radioactive cesium from the crippled Fukushima No. 1 nuclear power plant.
Spanning 13 prefectures, the affected area has accumulated more than 10,000 becquerels of cesium 134 and 137 per square meter, according to the science ministry.
The ministry has released the latest version of its cesium contamination map, covering 18 prefectures.
Radioactive plumes from the Fukushima No. 1 plant reached no farther than the border between Gunma and Nagano prefectures in the west and southern Iwate Prefecture in the north.
Ministry officials said the plumes flowed mainly via four routes between March 14 and 22 after the plant was damaged by the Great East Japan Earthquake and tsunami on March 11.
The first plume headed westward from late March 14 to early March 15, when huge amounts of radioactive materials were released following a meltdown at the No. 2 reactor.
It moved clockwise over a wide area in the Kanto region. Radioactive materials fell with rain and snow, particularly in the northern parts of Tochigi and Gunma prefectures.
A branch of the plume moved southward from Gunma Prefecture, passing through western Saitama Prefecture, eastern Nagano Prefecture and western Tokyo.
It stopped in western Kanagawa Prefecture, where the Tanzawa mountain range rises up.
The second plume headed northwest in the afternoon of March 15, heavily contaminating parts of Namie and other municipalities in Fukushima Prefecture.
The third plume headed northward, apparently in the afternoon of March 20.
Areas in northern Miyagi Prefecture and southern Iwate Prefecture were probably contaminated when it rained between the late afternoon of March 20 and early March 21.
The fourth plume headed southward from the night of March 21 and early March 22.
It passed through northern Chiba Prefecture but largely skirted central Tokyo due to a pressure pattern, limiting contamination in Tokyo and Kanagawa Prefecture.
It is believed that the amount of radioactive materials released from the Fukushima No. 1 plant increased between March 20 and 23, but the reasons are not yet known.
In Fukushima and seven other prefectures, 11,600 square kilometers, or 3 percent of Japan’s land area, have annual additional radiation levels of at least 1 millisievert, according to Environment Ministry estimates….”
Radiation dosimeter sales spiking since nuke disaster (Asahi, Nov 23)
A steady stream of customers in search of radiation dosimeters filled a store tucked away in an alley in Tokyo’s Akihabara district on Nov. 19.
A year ago, many of the Toyo Keisokuki store’s new clients would not have known what a dosimeter was, but in Japan since the accidents at the Fukushima No. 1 nuclear power plant, the meters are rapidly becoming a hot item.
More than 10 types of dosimeters line the shelves at Toyo Keisokuki, with price tags ranging from 30,000 yen to 200,000 yen (about $400 to $2,667).
The store says it has sold several hundred dosimeters since the disaster, often to parents or grandparents concerned about the threat of radiation to their children or grandchildren. Sales are up 10 times on previous years, when most buyers were engineers.
One of the new customers, Tsunehito Wake, 38, runs a firm in Tokyo’s Suginami Ward and has three young children aged between 1 and 5.
Concerned about the effects of radiation from the Fukushima disaster, he evacuated his children to Shikoku island in western Japan in March and is still concerned about contamination at his Tokyo-area home.
He brought in an expert to measure radiation levels in his garden, but was visiting Toyo Keisokuki on Nov. 19 to get his own dosimeter. He said he had searched for dosimeters on the Internet, but needed advice to work out which one to get.
“If the dosimeter shows a high radiation level that makes you anxious, you should report it to the local government,” a clerk told him.
Wake eventually bought a Russian-made dosimeter with a manual written in Japanese and priced between 30,000 yen and 40,000 yen.
Masami Ishibashi, an assistant at the store, said she always asks customers what they want to measure before selling anything.
Most dosimeters measure levels of radiation issued by radioactive materials in the air or accumulated on surfaces, but those meters cannot measure radioactive materials contained in food, a process which requires large and expensive equipment.
There are also significant differences between meters designed to measure environmental radiation, despite often having a similar outward appearance.
Geiger-Muller counters, for example, measure overall rays emitted from radioactive materials such as beta rays and gamma rays. Beta rays are only detectable near contaminated objects, making the counters well suited to checking contamination levels on surfaces where radioactive materials might have accumulated.
Scintillation counters, on the other hand, are favored by many local governments looking to detect threats to human health because they measure gamma rays, which have a longer range than beta rays and can harm the human body.
A whole range of other dosimeters, including semiconductor-type meters, are also available.
“Choosing equipment suitable for your purposes is the first step toward accurate measurement,” Ishibashi said.
Small paddies line a valley surrounded by mountains in Fukushima’s Onami district. Radioactive cesium exceeding national safety standards was detected in rice from the district on Nov. 15. (Naoko Kawamura)
Radioactive rice raises concerns about testing system(Asahi Nov 19) The government’s rice testing program failed to detect high levels of radioactive cesium in pre-harvest tests of rice from the Onami district of Fukushima, which was found to have produced rice significantly in excess of safety standards on Nov. 15.
Rice harvested this fall in the city of Fukushima’s Onami district registered radioactive cesium levels of 630 becquerels per kilogram, exceeding the government limit of 500 becquerels. The government has since ordered Fukushima Prefecture to ban shipments of rice from the area.
As none of the rice samples from Onami that had been tested before and after harvest were found to have radiation levels above the maximum limit, the rice had previously been cleared for distribution. In other words, had rice farmers not submitted samples for voluntary testing, it was possible that the rice could have reached the market. To protect the public, the government must get to the bottom of what caused such highly concentrated radioactive contamination, and establish a more reliable testing system.
After the nuclear crisis in Fukushima began, the government restricted rice planting in no-entry zones and other areas for the year, and additionally implemented a two-step, pre-harvest and post-harvest testing system in 17 prefectures to prevent the distribution of radiation-tainted rice. In the latest case, however, contaminated rice slipped through government safeguards.
Based on preliminary rice test results, some areas are designated “priority testing areas” that require close monitoring of rice for high concentrations of radiation. The designation, however, only requires further testing of one sample of rice for every 15 hectares of rice paddy, which is perfunctory and requires revision.
In September, rice produced in the Fukushima Prefecture city of Nihonmatsu’s Obama district was found in a preliminary test to have radiation levels exceeding the maximum limit. A month later, the Fukushima Prefectural Government compiled a mid-term report saying that the radioactive contamination found in Obama rice was “an extremely rare” phenomenon, attributing it to a combination of various factors such as the conditions of the soil and rice plants, as well as other environmental factors.
However, the case of Onami rice resembles that of Obama rice in that it was found to have highly concentrated levels of radiation. As such, isn’t it too soon to conclude that occurrences of heavily contaminated rice — like radiation hot spots — are “extremely rare?”
Situated in the mountains, the rice paddies in Obama used mountain runoff as their water source, and some experts say that high concentrations of cesium could have come from this runoff. The paddies in Onami are located in hollows and make use of river water as well, with some suggesting that radioactive materials in the surrounding environment could have accumulated in the water.
To protect consumers, it would be best to test all rice for radiation contamination. If that is unrealistic, the government at the very least should run more finely tuned tests on rice grown under conditions and environments resembling those in the cities of Fukushima and Nihonmatsu before they reach consumers.
In addition, there is an urgent need for the government to pinpoint the cause of contamination. Knowing that will allow us to sort out which areas should be given testing and decontamination priority, as well as whether or not rice can be planted next year.
Meanwhile, despite a rice crop index similar to that of other years, rice prices have remained high due to lacking supply. The latest case may drive this trend even further, especially among rice produced in western Japan, far from the Fukushima power plant. The government must keep a watchful eye to ensure safety and fair prices for the public.
The potentially lucrative business of decontaminating areas of radioactive substances released from Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power station may well go to companies handpicked by a government organization that has long played a leading role in promoting the construction of nuclear plants with the electric power industry.
If this becomes a reality, it is feared that much of the cleanup work will be undertaken by amateurs who have only gone through the “Decontamination 101” seminars certifying completion of rudimentary training to do the job.
Procedures for decontamination work, which has been necessitated by the disastrous accidents at the Fukushima No. 1 nuclear power plant after the March 11 earthquake and tsunami, are provided for in a special law enacted in August.
The government body rumored likely to be given the monopolistic power of deciding who will be awarded decontamination contracts under this law is the Japan Atomic Energy Agency (JAEA).
Professor Tatsuhiko Kodama, head of the University of Tokyo’s Radioisotope Center, has expressed anger over Article 56 of the law, which was enacted by the Democratic Party of Japan, the Liberal Democratic Party and Komeito without deliberations in the Diet. The article, suddenly inserted into the law just before voting, requires the environment minister to seek the opinions of the Nuclear Safety Commission (NSC) before issuing or revising related ordinances of the environment ministry.
The problem with this provision is that the NSC is staffed by only four experts in nuclear reactors and one in health hazards, while nobody is well-versed in measuring radiation levels and decontamination.
A researcher who has closely followed how this law was enacted suspects that the article in question represents a “counteroffensive” from pro-nuclear bureaucrats toward the government’s new policy of reducing Japan’s reliance on nuclear energy. He points out that the article is aimed at empowering the NSC to draw up standards for decontamination so that the actual cleanup work can be arbitrarily concentrated in the hands of the JAEA as the two are closely interrelated to each other.
The agency, which came into being in 2005 through the merger of the Power Reactor and Nuclear Fuel Development Corporation (PNA) and the Japan Atomic Energy Research Institute (AERI), has long collaborated closely with the electric power industry for promoting the construction of nuclear power-generating stations in Japan.
More than a few people feel that it is not right for the organization, which has long worked for expansion of the nuclear power plant network, to be given the principal task of cleaning up the contaminated areas, let alone on an almost exclusive basis.
“Undertaking decontamination work is not included in the JAEA’s mission and is not part of its capabilities,” professor Kodama asserts. “There are companies in the private sector that have the technology and the experience. Why does the JAEA have to do the job?”
The total cost of decontaminating all areas contaminated by radioactive substances from the Fukushima power plant is estimated to range from dozens of trillions of yen to ¥100 trillion. Goshi Hosono, the environment minister and minister in charge of nuclear accident settlement and prevention, has publicly stated the government would complete the job regardless of how much it costs.
On Sept. 30, the JAEA was entrusted with a ¥10 billion model decontamination project. It will assign the real work to companies with “certificates.” Since the real cost is estimated to be about ¥7.2 billion, some people criticized the JAEA’s getting a margin of some ¥3 billion. Full-scale contamination will be much more costly and money for individual decontamination work will come through the JAEA.
The agency has been active in holding seminars for those seeking to be awarded certificates and, eventually, contracts. The problem is that most of the participants are from construction and civil engineering companies equipped with heavy earth-moving machinery and high-pressure water hoses; they are mere amateurs when it comes to anything related to radioactivity.
Besides, each of these certificate seminars lasts only two days. On the first day, participants are taught such fundamentals as “an outline of the accident at the nuclear plant,” “the basics about radiation” and “how to handle radiation safely.” Only on the second day are they taught methods of decontamination. The textbook is only 12 pages.
Even this portion of the seminar goes only as far as where and how to store contaminated materials that have been collected. It fails to touch on the more fundamental issue of how to ultimately dispose of them.
Some JAEA officials have admitted lacking answers with regard to the final stage of decontamination because no concrete policies have been established.
After the two-day lectures, participants in the seminars are led to the field study of measuring radiation levels on grass surfaces and mountain sides. If they pass the subsequent written examinations, they are given the “certificate” qualifying them to undertake decontamination work.
With so many amateurs certified as “experts,” a number of unsatisfactory results have already been uncovered. Professor Tomoya Yamauchi at the Graduate School of Maritime Sciences at Kobe University, reports that a decontamination project undertaken by the JAEA for streets used by elementary school children in Fukushima City resulted in a reduction of radiation levels by only 32 percent.
Decontamination is such a technologically complicated process in the first place that there are many diversified and mutually conflicting views among scientists and experts as to how it should be approached. This makes it all the more important to seek a decontamination method that maximizes the effect and minimizes the cost through public debates.
If a blank check on decontamination procedures is given to the JAEA, which in the past had collaborated closely with the government and the electric power industry in promoting nuclear power generation, the whole cleanup processes will most likely be done in a haphazard manner.
Absent any decision on the final disposal of radioactive materials, such a haphazard process could indeed result in the further spread of radioactive materials.
A resident in a contaminated area lamented: “We are forced to take a backseat in the decontamination process. Benefits go only to the JAEA and companies with close ties with that organization.”
It is tragic indeed that decontamination work appears to be going along this line.
Future cancers from Fukushima plant may be hidden ((Mainichi, November 20, 2011)
UKUSHIMA, Japan (AP) — Even if the worst nuclear accident in 25 years leads to many people developing cancer, we may never find out.
Looking back on those early days of radiation horror, that may sound implausible.
But the ordinary rate of cancer is so high, and our understanding of the effects of radiation exposure so limited, that any increase in cases from the Fukushima nuclear plant disaster may be undetectable.
Several experts inside and outside Japan told The Associated Press that cancers caused by the radiation may be too few to show up in large population studies, like the long-term survey just getting under way in Fukushima.
That could mean thousands of cancers under the radar in a study of millions of people, or it could be virtually none. Some of the dozen experts the AP interviewed said they believe radiation doses most Japanese people have gotten fall in a “low-dose” range, where the effect on cancer remains unclear.
The cancer risk may be absent, or just too small to detect, said Dr. Fred Mettler, a radiologist who led an international study of health effects from the 1986 Chernobyl disaster.
That’s partly because cancer is one of the top killers of people in industrialized nations. Odds are high that if you live long enough, you will die of cancer. The average lifetime cancer risk is about 40 percent.
In any case, the 2 million residents of Fukushima Prefecture, targeted in the new, 30-year survey, probably got too little radiation to have a noticeable effect on cancer rates, said Seiji Yasumura of the state-run Fukushima Medical University. Yasumura is helping run the project.
“I think he’s right,” as long as authorities limit children’s future exposure to the radiation, said Richard Wakeford, a visiting epidemiology professor at the Dalton Nuclear Institute at the University of Manchester in England. Wakeford, who’s also editor of the Journal of Radiological Protection, said he’s assuming that the encouraging data he’s seen on the risk for thyroid cancer is correct.
The idea that Fukushima-related cancers may go undetected gives no comfort to Edwin Lyman, a physicist and senior scientist with the Union of Concerned Scientists, a group that advocates for nuclear safety. He said that even if cancers don’t turn up in population studies, that “doesn’t mean the cancers aren’t there, and it doesn’t mean it doesn’t matter.”
“I think that a prediction of thousands of cancer deaths as a result of the radiation from Fukushima is not out of line,” Lyman said. But he stressed that authorities can do a lot to limit the toll by reducing future exposure to the radiation. That could mean expensive decontamination projects, large areas of condemned land and people never returning home, he said. “There’s some difficult choices ahead.”
Japan’s Cabinet this month endorsed a plan to cut contamination levels in half within the next two years. The government recently announced it plans to study the risk from long-term exposure to the low-dose radiation level used as a trigger for evacuations.
The plant was damaged March 11 by a tsunami triggered by a magnitude-9 earthquake. Japanese authorities estimate it leaked about one-sixth as much radiation as the Chernobyl accident. It spewed radioactive materials like iodine-131, cesium-137 and 29 others contaminating the water, soil, forests and crops for miles around. A recent study suggested that emissions of cesium-137, were in fact twice what the government has estimated.
So far, no radiation-linked death or sickness has been reported in either citizens or workers who are shutting down the plant.
And a preliminary survey of 3,373 evacuees from the 10 towns closest to the plant this summer showed their estimated internal exposure doses over the next several decades would be far below levels officials deem harmful.
But while the Fukushima disaster has faded from world headlines, many Japanese remain concerned about their long-term health. And many don’t trust reassurances from government scientists like Yasumura, of the Fukushima survey.
Many consumers worry about the safety of food from Fukushima and surrounding prefectures, although produce and fish found to be above government-set limits for contamination have been barred from the market. For example, mushrooms harvested in and around Fukushima are frequently found to be contaminated and barred from market. Controversy has also erupted around the government’s choice of a maximum allowed level for internal radiation exposure from food.
Fukushima has distributed radiation monitors to 280,000 children at its elementary and junior high schools. Many children are allowed to play outside only two or three hours a day. Schools have removed topsoil on the playgrounds to reduce the dose, and the Education Ministry provided radiation handbooks for teachers. Thousands of children have been moved out of Fukushima since the March disasters, mainly due to radiation fears.
Many parents and concerned citizens in and around Fukushima, some even as far as Tokyo, carry Geiger counters for daily measurement of radiation levels in their neighborhoods, especially near schools and kindergartens. The devices are probably one of the most popular electronics gadgets across Japan these days. People can rent them at DVD shops or drug stores in Fukushima, while many Internet rental businesses specializing in Geiger counters also have emerged.
Citizens groups are also setting up radiation measuring centers where people can submit vegetables, milk or other foods for tests. Some people are turning to traditional Japanese diet — pickled plum, miso soup and brown rice — based on a belief that it boosts the immune system.
“I try what I believe is the best, because I don’t trust the government any more,” says Chieko Shiina, who has turned to that diet. The 65-year-old Fukushima farmer had to close a small Japanese-style inn due to the nuclear crisis.
She thinks leaving Fukushima would be safer but says there is nowhere else to go.
“I know we continue to be irradiated, even right at this moment. I know it would be best just to leave Fukushima,” she said.
Yuka Saito, a mother of four who lives in a Fukushima neighborhood where the evacuation order was recently lifted, said she and her three youngest children spent the summer in Hokkaido to get away from the radiation. She tells her children, ages 6 to 15, to wear medical masks, long-sleeved shirts and a hat whenever they go out, and not to play outside.
She still avoids drinking tap water and keeps a daily log of her own radiation monitoring around the house, kindergarten and schools her children attend.
“We Fukushima people are exposed to radiation more than anyone else outside the prefecture, but we just have to do our best to cope,” she said. “We cannot stay inside the house forever.”
Japanese officials say mental health problems caused by excessive fear of radiation are prevalent and posing a bigger problem than actual risk of cancer caused by radiation.
But what kind of cancer risks do the Japanese really face?
Information on actual radiation exposures for individuals is scarce, and some experts say they can’t draw any conclusions yet about risk to the population.
But Michiaki Kai, professor of environmental health at Oita University of Nursing and Health Sciences, said that based on tests he’s seen on people and their exposure levels, nobody in Fukushima except for some plant workers has been exposed to harmful levels of radiation.
Radiation generally raises cancer risk in proportion to its amount. At low-dose exposures, many experts and ‘regulators embrace the idea that this still holds true. But other experts say direct evidence for that is lacking, and that it’s not clear whether such small doses raise cancer risk at all.
“Nobody knows the answer to that question,” says Mettler, an emeritus professor of radiology at the University of New Mexico and the U.S. representative to the United Nations Scientific Committee on the Effects of Atomic Radiation, or UNSCEAR. If such low doses do produce cancers, they’d be too few to be detected against the backdrop of normal cancer rates, he said.
To an individual the question may have little meaning, since it deals with the difference between no risk and small risk. For example, the general population was told to evacuate areas that would expose them to more than 20 millisieverts a year. A millisievert measures radiation dose and 20 mSv is about seven times the average dose of background radiation Americans get in a year. A child exposed to 20 mSv for a year would face a calculated risk of about 1 in 400 of getting cancer someday as a result, says David Brenner of Columbia University. So that would add 0.25 percent onto the typical lifetime cancer risk of about 40 percent, he said.
And the average dose among the 14,385 workers who worked on the plant through July was 8 mSv, according to the Japanese government. The average lifetime risk of cancer to an individual from that dose alone would be calculated at about 0.05 percent, or 1 in 2,000, Brenner said.
Brenner stresses that such calculations are uncertain because scientists know so little about the effects of such small doses of radiation.
But in assessing the Fukushima disaster’s effect on populations, the low-dose question leads to another: If a lot of people are each exposed to a low dose, can you basically multiply their individual calculated risks to forecast a number of cancers in the population?
Brenner thinks so, which is why he believes some cancers might even appear in Tokyo although each resident’s risk is “pretty minuscule.”
But Wolfgang Weiss, who chairs the UNSCEAR radiation committee, said the committee considers it inappropriate to predict a certain number of cancer cases from a low-dose exposure, because low-dose risk isn’t proven.
Nuclear accidents can cause cancer of the thyroid gland, which can absorb radioactive iodine and become cancerous. That disease is highly treatable and rarely fatal.
After the Chernobyl disaster, some 6,000 children exposed to radioactive fallout later developed thyroid cancer. Experts blame contaminated milk. But the thyroid threat was apparently reduced in Japan, where authorities closely monitored dairy radiation levels, and children are not big milk drinkers anyway.
Still, the new Fukushima survey will check the thyroids of some 360,000 young people under age 18, with follow-ups planned every five years throughout their lifetimes. It will also track women who were pregnant early in the crisis, do checkups focused on mental health and lifestyle-related illnesses for evacuees and others from around the evacuation zone, and ask residents to fill out a 12-page questionnaire to assess their radiation exposure during the first weeks of the crisis.
But the survey organizers are having trouble getting responses, partly because of address changes. As of mid-October, less than half the residents had responded to the health questionnaire.
Some residents are skeptical about the survey’s objectivity because of mistrust toward the government, which repeatedly delayed disclosing key data and which revised evacuation zones and safety standards after the accident. Also, the government’s nuclear safety commission recommended use of iodine tablets but none of the residents received them just before or during evacuation, when the preventive medicine would have been most effective.
Some wonder if the study is using them as human guinea pigs to examine the impact of radiation on humans.
Eisuke Matsui, a lung cancer specialist and a former associate professor at Gifu University School of Medicine, criticized the project. He said it appears to largely ignore potential radiation-induced health risks like diabetes, cataracts and heart problems that have been hinted at by some studies of Chernobyl.
“If thyroid cancer is virtually the only abnormality on which they are focusing, I must say there is a big question mark over the reliability of this survey,” he said.
He also suggested sampling hair, clipped nails and fallen baby teeth to test for radioactive isotopes such as strontium that are undetectable by the survey’s current approach.
“We should check as many potential problems as possible,” Matsui said.
Yasumura acknowledges the main purpose of his study is “to relieve radiation fears.” But Matsui says he has a problem with that.
“A health survey should be a start,” Matsui says, “not a goal.”
Tatsuhiko Kodama, head of the Radioisotope Center at the University of Tokyo, urged quick action to determine the cancer risks.
He said big population surveys and analysis will take so long that it would make more sense to run a careful simulation of radiation exposures and do anything possible to reduce the risks.
“Our responsibility is to tell the people now what possible risks may be to their health,” he said.
Nuke crisis sends hundreds of Tokyoites fleeing to Okinawa (Asahi, Nov 22) Extracts below:
“NAHA, Okinawa Prefecture–Following the Fukushima nuclear crisis and fearing the spread of radiation, a number of Kanto residents fled to this southernmost prefecture and continue to live here despite the lack of personal connections.
“The Okinawans are really warm-hearted. I wouldn’t want to live in Tokyo again,” said Jin Tanimura, 38, clad in “kariyushi” wear, a locally promoted attire that looks like a Hawaiian shirt.
Following the nuclear crisis, more people have moved out of Tokyo and surrounding areas to Okinawa and other parts of western Japan than have moved in. Some well-known figures, including the writer Hitomi Kanehara, have openly said they evacuated out of the region to safety.
No data is available on the number of evacuees from the Tokyo metropolitan area to Okinawa, but local sources suggested there were hundreds.
The evacuees chose Okinawa because “it is far removed from Fukushima, it hosts no nuclear plant, and because Japanese is spoken there,” the sources said.
That sense of fear drove Tanimura, his wife, child, younger brother and sister-in-law to evacuate to Kyushu after the crisis began to unfurl at the Fukushima No. 1 nuclear power plant on March 11.
A search for a place devoid of nuclear plants led the family of five to Okinawa, although they had no relatives in the prefecture. It was only here that they could finally feel comfortable enough to take off their protective masks. They have lived in Okinawa for five months.
“The risk of radiation is fundamentally different from other risks,” Tanimura said. “It is invisible, and information is of mixed quality, and there are so many things that you don’t understand. That’s what makes it scary.”
Tanimura established in July a company to measure radiation levels in food in hopes of alleviating anxieties over shopping. However, the business has yet to gain any traction, and Tanimura is living off his savings.
Currently there are active exchanges among the Tokyo evacuees. Mari Takenouchi, 44, who has been advocating against the danger of nuclear plants and earthquakes for more than 10 years, hosted a meeting for evacuees at her Naha apartment.
Takenouchi also has translated books on low-level radiation exposure.
“The accident was of such an extent, but the government kept saying it was safe,” she said. “I could no longer believe in the government.”
Immediately following the crisis, she evacuated along with her son, who would soon turn 2. Both of them had suffered from health problems, with frequent fevers, she said.
Takenouchi said she remains seriously concerned about the expanding threat to residents’ health.
“Internet sources say that a growing number of people are having health problems in the Tokyo metropolitan area,” she said. “This will result in an awful outcome if the situation continues.”
Takenouchi is organizing lectures and demonstrations. She has also set up a “Society of Hibakusya,” where “hibakusya” means sufferers of radiation exposure.
Mamiko Yanaka, 44, who co-directs the Society of Hibakusya with Takenouchi, appeared to be suffering even as she sat.
“I feel sluggish,” she said.
Yanaka quit her job and came to Okinawa in July after sensing that her health was failing.
She used to suffer from a thyroid gland disease. Following the Fukushima crisis, she mostly stayed at home out of fear of radiation, but still suffered from nosebleeds, diarrhea and other symptoms.
A search for information on the Internet led her to the conviction that she was suffering from low-level radiation, but “nobody took me seriously at any of the eight clinics I visited,” she said. …” Read more here.
A huge amount of debris along Japan’s eastern coast has been hampering the activity of fishing boats following the March 11th tsunami. The government says it will complete clearing away the debris by March 2014. Wreckage of houses, boats, and vehicles is still drifting at sea or has sunk to the bottom along the coast of the Tohoku Region, the northernmost prefecture of Hokkaido, and the Kanto Region.
The debris is impeding navigation of vessels in and out of ports and fishing activities, which have resumed after the disaster.
The Environment Ministry and Land and Transport Ministry worked out guidelines to clear away the debris and informed the 7 prefectures, including Hokkaido and Chiba.
The guidelines say that the debris at fishing ports should be cleared away by prefectures and local municipalities by the end of this year.
In sea areas where trawl fishing takes place, debris will be cleared away by the end of the current fiscal year in March.
All the gathered debris will be incinerated or put into a landfill by the end of March 2014.
The guidelines say the salt content of debris in sea water may cause corrosion of incineration facilities, and that wood debris should be exposed to the elements after being collected to get rid of salt before burning.
N-plant cold shutdown possible this year (Yomiuri, Nov.19)
Amid the chaos on March 11 as the crisis at the Fukushima No. 1 nuclear plant started to spiral out of control, workers manually shut down an “isolation condenser,” or a cooling device in the plant’s No. 1 reactor, Tokyo Electric Power Co. said on Nov. 22.
The workers were concerned that continued operation of the isolation condenser could damage the equipment and lead to a discharge of radioactive substances, according to TEPCO, the plant operator.
The circumstances behind shutting down the isolation condensers–the only means to cool the core of the No. 1 reactor where a meltdown first occurred–are a focus of an investigation by the government’s Investigation Committee on the Accident at the Fukushima Nuclear Power Stations.
Whether the decision to shut down the condenser was appropriate may emerge as a subject for review.
Only the No. 1 reactor is equipped with isolation condensers, which can cool vapor from the nuclear reactor, turn it into water and recycle that water to cool the reactor core. The equipment is made of two channels. At each condenser, vapor is sent through a pipe that runs inside a tank filled with water. The devices can function even if the power supply is lost.
TEPCO said the loss of power supply following the tsunami spawned by the Great East Japan Earthquake made it impossible to tell whether the isolation condensers were operating or not.
The condensers were later confirmed as having stopped when the power supply was restored temporarily.
At 6:18 p.m., workers opened motorized valves to set one of the condensers in motion, but the generation of vapor, due to the heating of water in the tank, was not confirmed, so the workers closed a valve at 6:25 p.m. to shut down the operation. The workers thought it possible that the tank contained no water, which would have meant that continued operation could damage the piping and lead to a release of vapor containing radioactive substances, TEPCO officials said.
An on-site survey in October found out that the water level remained at about 65 percent of the capacity of the tank.
The workers reopened the valve at 9:30 p.m. TEPCO said that the equipment retained only limited functionality and that the core meltdown would have been inevitable at any rate, even if continued operation could have delayed it to a certain extent.
TEPCO’s analysis suggested that a core meltdown would have occurred four hours after the earthquake hit at 2:46 p.m. if the isolation condensers had not operated, and would have taken place in seven hours, or some time before 10 p.m., even if the condensers had begun operating at around 6 p.m.
The decision to shut down the operation was made by workers in the central control room, including the chief worker on duty, but it is not known if the director and other senior officials of the nuclear plant were informed of the decision, TEPCO officials said.
More than half of the prefectures polled by the Environment Ministry do not plan to accept post quake-disaster debris.
Govt official dumps radiation-contaminated soil (NHK, November 17)
An Environment Ministry official has dumped radiation-contaminated soil near his home in Saitama Prefecture, near Tokyo.
Environment Minister Goshi Hosono revealed this at a news conference on Thursday.
He said a cardboard box containing the soil was sent to his ministry on November 8th from a sender who identifies himself as a resident of Fukushima City.
An enclosed message calls on the ministry to store and dispose of the soil collected from the sender’s garden.
The Environment Ministry kept the soil in its warehouse, and the radiation reading taken close to it was 0.18 microsieverts per hour.
A section chief at the ministry said this is no higher than readings taken in many areas in and around Tokyo and suggested he could dispose of the soil in his own garden.
His subordinate then dumped the soil in a vacant lot near his home on Sunday.
This was revealed after another box marked as “ash” was sent to the ministry apparently from the same sender on Wednesday.
The ministry is said to have already retrieved the soil and plans to dispose of it appropriately.
Hosono said he takes the inappropriate dumping of the soil very seriously and apologized. He said it should not have happened, as his ministry has been playing a central role in efforts to clean up areas contaminated with radiation.
Hosono said he will punish the section chief and study taking punitive actions against other senior officials, including himself.
He also said sending radiation-contaminated materials to his ministry will not lead to a fundamental solution to the problem, and called on people not to do so.
Fukushima saw fewer births after nuclear disaster (NHK, November 18, 2011)
A survey in Fukushima Prefecture shows the number of births fell by 25 percent in the 3 months following the accident at the nuclear power plant.
The Japan Association of Obstetricians and Gynecologists conducted a nationwide survey of around 1,100 medical institutions handling deliveries between April and June. 714 responded.
The number of births per institution in Fukushima came to 67, down from 90 in the same period last year.
This means there were 1,000 less deliveries in the prefecture during the 3-month period than a year earlier.
The combined number of deliveries in Tokyo, Chiba and Kanagawa is also estimated to have decreased by around 2,000 in the same period.
On the other hand, some prefectures further west such as Fukuoka, Gifu and Osaka saw more babies born than a year earlier.
Professor Akihito Nakai of Nippon Medical School took part in the survey. He says the findings show that many women chose to give birth away from their homes because they were concerned about radioactive contamination.
He is calling on authorities to work out measures to help these mothers deal with heavy psychological burdens.
Nearly 90% would prefer domestic rice (Yomiuri, Nov.21)
Nearly 90 percent of respondents to a nationwide Yomiuri Shimbun survey said they would primarily choose Japanese rice over foreign brands even if the latter cost less after rice imports were liberalized.
The survey also showed 68 percent were in favor of increasing the number of large-scale farming operations to boost Japan’s agricultural productivity, compared with 19 percent who were opposed.
The survey was conducted on Nov. 12-13 among 3,000 randomly selected eligible voters in 250 locations across the country. Interviews were conducted at the pollees’ homes with 1,724, or 57 percent, responding.
Women accounted for 53 percent of the respondents.
Asked what they thought about the possibility of the government increasing its direct subsidies to individual farmers, 59 percent of the pollees supported the idea, compared to 29 percent who did not.
Eighty percent of people thought it was advisable to provide people engaging in farming for the first time with government subsidies, while 15 percent opposed the idea.
Eighty percent of people thought it was advisable to provide people engaging in farming for the first time with government subsidies, while 15 percent opposed the idea.
Respondents who favored allowing businesses to freely enter the agricultural field stood at 62 percent, compared to 27 percent who did not approve.
These findings appear to indicate that most people would support a package of government steps designed to help reinvigorate the nation’s agriculture.
Asked if they would continue buying domestic rice even after low-priced rice from overseas became available under trade liberalization, 89 percent of the respondents said they would purchase primarily Japanese-made rice, while 7 percent said they would buy primarily rice from abroad.
Five percent gave no answer.
Another survey question was, “Do you think Japan should take part in the Trans-Pacific Partnership negotiations aimed at liberalizing trade, including agriculture, in the Pacific Rim?”
Forty-one percent favored Japan’s participation in the TPP talks, while 37 percent were opposed and 22 percent gave no answer.
Asked about the impression they had of domestic farm produce, the most popular response was “very safe” with 73 percent. It was followed by “tasty” with 72 percent and “fresh” with 64 percent, while 22 percent said domestic farm products were “expensive.”
More than one answer was possible.
On farm produce from abroad, the most common impression was “low safety” with 76 percent, followed by “inexpensive” with 46 percent and “not fresh” with 33 percent.